Question

A toy rocket was launched from the ground. The function f(x) = -16x2 + 160x shows the height of the rocket f(x), in feet, from the ground at time x seconds.

Answer 1

x = 10; it takes 10 seconds to reach the maximum height and 10 seconds to fall back to the ground

x = 10; it takes 10 seconds to reach the maximum height and 20 seconds to fall back to the ground

x = 5; it takes 5 seconds to reach the maximum height and 10 seconds to fall back to the ground

x = 5; it takes 5 seconds to reach the maximum height and 5 seconds to fall back to the ground

Answer 2

alright so we can use the vertex formula to find its max height.

Answer 3

\[x=-b/2a\]

Answer 4

yes

Answer 5

-160/-32

Answer 6

x=5 then y=?

Answer 7

Take the derivative and set it equal to zero and solve from the max

f'x = -32x +160 =0

x = 5

Then to solve from the time for when the ball hits the ground just solve the equation at 0

x(-16x +160) = 0, 10

Answer 8

is it C

Answer 9

hmm

Answer 10

x is our seconds

Answer 11

at x=10 we are at a height of 0

Answer 12

at x=5 we are at our max height

Answer 13

so it looks to me that it takes 5 seconds for it to fall back down to zero